Chapter 4 Flashcards
1
Q
Tissue
A
a group of cells that usually have a common origin in an embryo and function together to carry out specialized activities.
2
Q
Histology
A
the science that deals with the study of tissues.
3
Q
Pathologist
A
a physician who examines cells and tissues to help other physicians make accurate diagnoses.
4
Q
Body tissues can be classified into 4 basic types based on function and structure. What are these 4 types
A
Epithelial tissue, Connective Tissue, Muscular tissue, Nervous Tissue
5
Q
Epithelial Tissue
A
covers body surfaces and lines hollow organs,
body cavities, and ducts; it also forms glands. This tissue allows the
body to interact with both its internal and external environments.
6
Q
Connective Tissue
A
protects and supports the body and its organs.
Various types of connective tissues bind organs together, store
energy reserves as fat, and help provide the body with immunity to
disease-causing organisms.
7
Q
Muscular Tissue
A
composed of cells specialized for contraction and generation of force. In the process, muscular tissue generates
heat that warms the body.
8
Q
Nervous Tissue
A
detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve action potentials (nerve impulses) that activate muscular contractions and glandular secretions.
9
Q
Cell Junctions
A
are contact points between the plasma membranes of tissue cells.
10
Q
Five most important types of cell junctions
A
tight junctions, adherens junctions, desmosomes,
hemidesmosomes, and gap junctions
11
Q
Tight Junctions
A
consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells
12
Q
Adherens Junctions
A
plaque (PLAK), a dense
layer of proteins on the inside of the plasma membrane that attaches
both to membrane proteins and to microfilaments of the cytoskeleton. Adherens junctions help epithelial
surfaces resist separation during various contractile activities.
13
Q
Cadherins
A
Transmembrane glycoproteins that join the cell
14
Q
Adhesion Belts
A
In epithelial cells, adherens junctions oft en form extensive
zones called adhesion belts
15
Q
Desmosomes
A
contain plaque and have transmembrane glycoproteins (cadherins) that extend into the intercellular space between adjacent cell membranes and attach cells to one another. the plaque of desmosomes does not attach to microfilaments.
16
Q
Hemidmosomes
A
resemble desmosomes, but they do not link adjacent cells.
17
Q
Integrins
A
the transmembrane
glycoproteins in hemidesmosomes
18
Q
Laminin
A
On the outside of the
plasma membrane, the integrins attach to the protein.
19
Q
Gap Junctions
A
membrane proteins called connexins form tiny fluid-filled tunnels called connexons that connect neighboring cells.
20
Q
Comparison between
Epithelial and Connective
Tissues
A
The first obvious difference is the number of cells in relation
to the extracellular matrix (the substance between cells). The second obvious difference is that an epithelial tissue has
no blood vessels, whereas most connective tissues have significant networks of blood vessels.
21
Q
Epithelial Tissue
A
consists of cells arranged in continuous sheets, in either single or multiple layers. Epithelial tissue protects, secretes (mucus, hormones, and enzymes), absorbs (nutrients in the gastrointestinal tract), and excretes (various
substances in the urinary tract).
22
Q
3 different Surfaces of Epithelial Cells
A
Apical Surface, Lateral Surface, Basal Surface
23
Q
Apical Surface
A
faces the body surface, a body cavity, the
lumen (interior space) of an internal organ, or a tubular duct that
receives cell secretions. May contain cilia and microvili
24
Q
Lateral Surface
A
face the adjacent cells on either side, may contain tight junctions, adherens junctions, desmosomes, and/or gap junctions.
25
Basal Surface
Deepest layer of cells
26
Basement membrane
thin extracellular layer that commonly consists of two layers, the basal lamina and reticular lamina. Attaches to and anchors the epithelium to its underlying connective tissue. Form a surface along which epithelial cells migrate during growth or wound healing, restrict passage of larger molecules between epithelium and connective tissue, and participate in filtration of blood in the kidneys.
27
Basal Lamina
It contains proteins such as laminin and collagen as well as glycoproteins and proteoglycans
28
Reticular Lamina
contains proteins such as collagen produced by connective
tissue cells called fibroblasts
29
Avascular
Epithelial tissue is avascular and has its own nerve supply. Relying on the
blood vessels of the adjacent connective tissue to bring nutrients and remove wastes.
30
Exchange of substances between an epithelial tissue
and connective tissue occurs by
Diffusion
31
Different roles of Epithelial Tissue
protection, filtration, secretion, absorption, and excretion.
32
Epithelial Tissue Divided into 2 types
Covering and
lining epithelium and Glandular epithelium.
33
Covering and
lining epithelium
forms the outer covering of the skin and some internal organs. It also forms the inner lining of
blood vessels, ducts, body cavities, and the interior of the respiratory,
digestive, urinary, and reproductive systems.
34
Glandular epithelium
makes up the secreting portion of glands such as the thyroid gland,
adrenal glands, sweat glands, and digestive glands.
35
Arrangement of cell layers
Simple Epithelium, Pseudostratified epithelium, Stratified epithelium
36
Simple Epithelium
a single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption. Secretion
is the production and release of substances such as mucus,
sweat, or enzymes. Absorption is the intake of fluids or other
substances such as digested food from the intestinal tract.
37
Pseudostratified epithelium
multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface; it is actually a simple epithelium because all its cells rest on the basement membrane. Cells that do extend to the apical surface may contain cilia; others (goblet cells) secrete mucus.
38
Stratified epithelium
consists of two or more
layers of cells that protect underlying tissues in locations where there is considerable wear and tear.
39
Classification of Epithelial Tissue
1) the arrangement of cells into layers and 2) the shapes of the cells
40
Cell Shapes
Squamous cells, . Cuboidal cells, Columnar cells, Transitional cells
41
Squamous cells
thin, which allows for the
rapid passage of substances through them.
42
Cuboidal cells
tall as they are wide and are shaped like
cubes or hexagons. They may have microvilli at their apical surface and function in either secretion or absorption.
43
Columnar cells
taller than they are wide, like columns, and protect underlying tissues. Their apical surfaces may have cilia or microvilli, and they oft en are specialized for secretion
and absorption.
44
Transitional cells
change shape, from squamous to cuboidal
and back, as organs such as the urinary bladder stretch (distend) to a larger size and then collapse to a smaller size.
45
Simple epithelium
A. Simple squamous epithelium
1. Endothelium (lines heart, blood vessels, lymphatic vessels)
2. Mesothelium (forms epithelial layer of serous membranes)
B. Simple cuboidal epithelium
C. Simple columnar epithelium
1. Nonciliated (lacks cilia)
2. Ciliated (contains cilia)
D. Pseudostratified columnar epithelium
1. Nonciliated (lacks cilia)
2. Ciliated (contains cilia)
46
Stratified epithelium
A. Stratified squamous epithelium*
1. Nonkeratinized (lacks keratin)
2. Keratinized (contains keratin)
B. Stratified cuboidal epithelium*
C. Stratified columnar epithelium*
D. Transitional epithelium or urothelium (lines most of urinary tract)
47
Function of Glandular Epithelium
secretion, which is accomplished by glandular cells that oft en lie in clusters deep to the covering and lining epithelium.
48
Gland
consists of epithelium that secretes
substances into ducts (tubes), onto a surface, or eventually into the blood in the absence of ducts.
49
Two type of glands
Endocrine and Exocrine
50
Endocrine Glands
Secretions are called hormones, enter the interstitial fluid and then diffuse into the bloodstream without flowing through
a duct.
51
Exocrine Glands
secrete their products into ducts that empty onto the surface of a covering and lining epithelium such as the skin surface or the lumen of a hollow organ.
52
Structural Classification of Exocrine Glands
Unicellular and multicellular
53
Simple Gland
gland does not branch
54
Compound Gland
duct
branches
55
Tubular Glands
Glands with tubular secretory parts
56
Acinar Glands
those with rounded secretory
portions
57
Tubuloacinar glands
both tubular and more
rounded secretory parts.
58
Merocrine Gland
are synthesized on ribosomes attached to rough ER; processed,
sorted, and packaged by the Golgi complex; and released from the
cell in secretory vesicles via exocytosis.
59
Apocrine Gland
accumulate their secretory product at the apical surface of the
secreting cell. Then, that portion of the cell pinches off by exocytosis
from the rest of the cell to release the secretion
60
Holocrine Gland
accumulate a secretory product in their cytosol. As the secretory cell matures, it ruptures and becomes the
secretory product
61
Connective Tissue
one of the most abundant and widely distributed tissues in the body
62
Functions of Connective Tissue
t binds together, supports, and strengthens
other body tissues; protects and insulates internal organs; compartmentalizes structures such as skeletal muscles; serves as the major
transport system within the body (blood, a fluid connective tissue);
is the primary location of stored energy reserves (adipose, or fat,
tissue); and is the main source of immune responses.
63
2 basic elements of Connective Tissue
extracellular matrix
and cells.
64
extracellular matrix
is the material located between its widely spaced cells. The extracellular matrix
consists of protein fibers and ground substance, the material between the
cells and the fibers.
65
Connective Tissue Cells
Fibroblasts, Macrophages, Plasma Cells, Mast Cells, Adipocytes, Leukocytes
66
Fibroblasts
large, flat cells with
branching processes. They are present in all the general connective
tissues, and usually are the most numerous.
67
Macrophages
phagocytes that develop from monocytes, a type of white blood
cell. Two types: Fixed and Wandering
68
Plasma Cells
most plasma cells reside in connective tissue, especially in the
gastrointestinal and respiratory tracts.
69
Mast Cells
involved in the inflammatory response,
the body’s reaction to injury or infection and can also bind to,
ingest, and kill bacteria.
70
Adipocytes
fat cells, connective
tissue cells that store triglycerides (fats). They are found deep to
the skin and around organs such as the heart and kidneys.
71
Leukocytes (WBC)
in response to certain
conditions they migrate from blood into connective tissue.
72
The extracellular
matrix consists of two major components:
(1) the ground substance
and (2) the fibers
73
Ground Substance
the component of a connective tissue between the cells and fibers. It supports cells, binds them together, stores water, and provides a medium for exchange of substances between the blood and cells.
74
Hyaluronic Acid
a viscous, slippery substance that binds cells together, lubricates joints, and helps maintain
the shape of the eyeballs.
75
Fibers
are embedded in the extracellular
matrix between the cells: collagen fibers, elastic fibers, and reticular
fibers. They function to strengthen and support connective tissues.
76
Collagen Fibers
very strong and resist pulling or stretching, but they are not stiff , which allows tissue
flexibility.
77
Elastic Fibers
An elastic fiber consists of molecules of the protein elastin surrounded by a glycoprotein named fibrillin, which adds strength and
stability. strong but can be stretched up to 150% of their relaxed length without
breaking
78
Reticular Fibers
provide support and strength.
79
Stroma
supporting
framework) of many soft organs, such as the spleen and lymph nodes.
80
Classification of Connective Tissue
I. Embryonic connective tissue
A. Mesenchyme
B. Mucous (mucoid) connective tissue
II. Mature connective tissue
A. Connective tissue proper
1. Loose connective tissue
a. Areolar connective tissue
b. Adipose tissue
c. Reticular connective tissue
2. Dense connective tissue
a. Dense regular connective tissue
b. Dense irregular connective tissue
c. Elastic connective tissue
B. Supporting connective tissue
1. Cartilage
a. Hyaline cartilage
b. Fibrocartilage
c. Elastic cartilage
2. Bone tissue
a. Compact bone
b. Spongy bone
C. Liquid connective tissue
1. Blood
2. Lymph
81
Embryonic connective tissue
connective tissue present in an embryo or a fetus.
82
Mature connective tissue
connective tissue that is present at birth and persists throughout life.
83
connective tissue proper
flexible and contains a viscous ground substance with abundant
fibers.
84
supporting
connective tissue
protects and supports soft tissues of the
body.
85
liquid connective tissue
extracellular matrix is liquid.
86
Two Types of Embryonic Connective Tissue
mesenchyme and mucous connective tissue
87
Connective Tissue Proper
flexible and has a viscous ground substance with abundant
fibers.
88
Loose Connective Tissue
Loosely arranged between cells
89
Types of Connective Tissue
areolar connective tissue, adipose tissue, and reticular
connective tissue
90
Dense Connective Tissue
contains more fibers, which are thicker and more densely packed, but have considerably fewer cells than loose connective tissue.
91
Types of Dense Connective Tissue
dense regular
connective tissue, dense irregular connective tissue, and elastic connective tissue
92
Cartilage
consists of a dense network of collagen fibers and elastic fibers firmly embedded in chondroitin sulfate, a gel-like component of the ground substance.
93
Chondrocytes
The cells of mature cartilage. occur singly or in groups within spaces called lacunae.
94
Perichondrium
surrounds the surface of most cartilage and contains blood vessels and nerves and is the source of new cartilage cells.
95
3 types of cartilage
hyaline cartilage, fibrocartilage, and elastic cartilage
96
The growth of cartilage follows two basic
patterns:
interstitial growth and appositional growth.
97
Interstital growth
growth from
within the tissue.
98
Appositional Growth
growth at the
outer surface of the tissue.
99
Bone Tissue
Cartilage, joints, and bones make up the skeletal system. classified as either compact
or spongy, depending on how its extracellular matrix and cells are
organized.
100
Basic Unit of Compact Bone
Osteon
101
Osteon has 4 parts
Lamallae, Lacunae, canaliculi, central canal
102
Lamallae
concentric rings of extracellular matrix that consist of mineral salts
(mostly calcium and phosphates), which give bone its hardness
and compressive strength, and collagen fibers, which give bone its tensile strength. The lamellae are responsible for the compact nature of this type of bone tissue.
103
Lacunae
are small spaces between lamellae that contain mature bone cells called osteocytes.
104
Canaliculi
networks of minute canals containing the processes of
osteocytes. Canaliculi provide routes for nutrients to reach osteocytes and for wastes to leave them.
105
Central Canal
contains blood vessels and nerves.
106
Spongy Bone
Lacks osteons, consists of trabeculae
107
Liquid Connective Tissue
liquid as its
extracellular matrix. Ex) Blood
108
Examples of Liquid Connective Tissue
Blood, Lymph
109
Membranes
flat sheets of pliable tissue that cover or line a part of the body. The majority of membranes consist of an epithelial layer and an underlying connective tissue layer and are called epithelial
membranes.
110
Types of Epithelial Membranes
mucous membranes, serous membranes, and the cutaneous membrane, or skin.
111
Mucous Membranes
lines a body cavity that opens directly to the exterior.
112
Lamina Propria
The connective tissue layer of a mucous membrane that is an areolar connective tissue
113
Serous Membranes
lines a body cavity that does not open directly to the exterior
(thoracic or abdominal cavities), and it covers the organs that are
within the cavity.
114
Two Layers of Serous Membranes
Parietal Layer and Visceral Layer
115
Serous Fluid
mesothelium
of a serous membrane secretes this
116
Cutaneous Membrane
covers the entire surface of the body and consists
of a superficial portion called the epidermis and a deeper portion
called the dermis
117
Synovial Membranes
line the cavities of freely movable joints (joint cavities).
118
Muscular Tissue
consists of elongated cells called muscle fibers or myocytes that can use ATP to generate force. As a result, muscular
tissue produces body movements, maintains posture, and generates
heat. It also provides protection.
119
3 types of Muscular Tissue
skeletal, cardiac, and smooth
120
Skeletal Muscular Tissue
consists of long, cylindrical, striated fibers (striations are alternating light and dark bands within fibers
that are visible under a light microscope). Motion, posture, heat production, protection.
121
Cardiac Muscular Tissue
consists of branched, striated fibers with usually only one centrally located nucleus (occasionally two). Pumps blood to all parts of the body.
122
Smooth Muscle Tissue
nonstriated fibers (lack striations, hence the term smooth). Motion (constriction of blood vessels and airways, propulsion of foods through gastrointestinal tract, contraction of urinary bladder
and gallbladder).
123
Nervous Tissue
consists of only two principal types of cells: neurons and neuroglia.
124
Neurons
are sensitive to various stimuli. They convert stimuli into electrical signals called nerve action potentials.
125
3 parts of Neurons
a cell body and two kinds of cell processes—dendrites and axons
126
Function of Nervous Tissue
Exhibits sensitivity to various types of stimuli; converts stimuli into nerve impulses (action potentials); conducts nerve impulses to
other neurons, muscle fibers, or glands.
127
Excitable Cells
Neurons and muscle fibers are considered excitable cells because
they exhibit electrical excitability,
128
Electrical Excitability
the ability to respond to certain stimuli by producing electrical signals such as action potentials.
